Space.com reports that "the United States military is making progress toward developing a new unmanned space plane, which it aims to begin flight-testing in 2017."

"The Defense Advanced Research Projects Agency (DARPA) plans to award the first design contracts for the vehicle project — known as Experimental Spaceplane, or XS-1— in May or thereabouts, officials said. Current schedules call for the vessel to get off the ground for the first time in late 2017 and make an orbital test flight the following year."

"DARPA has high expectations for the XS-1 program, which it hopes can eventually launch 3,000- to 5,000-lb (1,361 to 2,268 kilograms) payloads to orbit for less than $5 million per flight — and to do it at least 10 times per year."